Because carbon nanotubes (CNT) have characteristics such as the mechanical strength is high, they are lightweight, the electricity conducting characteristic is good, the thermal characteristics are good, the field electron emission characteristic is good and the like, attention is being given to the application of carbon nanotubes to probes for scanning probe microscopes (SPM), electrodes for field emission displays (FED), electroconductive resins, high-strength fiber-strengthened resins, corrosion resistant resins, wear resistant resins, high lubricating resins, electrodes of secondary batteries and fuel cells, inter-layer wiring materials of LSIs, biosensors, and the like.
As methods of producing carbon nanotubes, there are, for example, arc discharge, laser evaporation, chemical vapor deposition (CVD) and the like, and a method of producing carbon nanotubes by CVD is disclosed in Patent Document 1.
In CVD, basically, a catalyst metal and a hydrocarbon that is a carbon source are made to coexist, and carbon nanotubes are synthesized at a process temperature of, for example, from 650° C. to 1300° C. When the size of the catalyst particles is small, single-layer carbon nanotubes (SWNT) are obtained. There are many variations in the type of the catalyst, the way of supporting thereof (floating on the substrate and the like).
For example, there is a technique of forming carbon nanotubes by sputtering or the like a metal film such as iron or aluminum or the like as a catalyst on a plate-shaped substrate, and, in a state in which this is set in an electric furnace and the electric furnace interior is raised to a predetermined temperature, bleeding a gas, in which acetylene and hydrogen, ammonium or the like are blended, into the electric furnace and causing it to chemically react with the catalyst, thereby orienting the carbon nanotubes vertically on the substrate.    Patent Document 1: Japanese Patent Application Laid-Open No. 2006-265006    Patent Document 2: US Patent Application Publication US20080170982A1    Patent Document 3: Japanese Patent Application National Publication No. 2008-517182    Patent Document 4: Japanese Patent No. 3954967    Patent Document 5: Japanese Patent Application National Publication No. 2008-523254